Urea-aldehyde plasticized resin and process of making the same



Patented Mar. 20,

UBEA-ALDEHYDE PLASTIGIZED AND PROCESS OF MAKING THE SAME Emil E. Novotny and Wilmott W. Johnson, Philadelphia, Pa, minors to John Stogdell Stokes. Huntingdon Valley, Pa.

No Drawing. Original application October 1, 1924, Serial N0. 741,053. Divided m a!!! lib plication June 16, i931. Serial N0. 544,928

3 Claims. (cries-mi This invention relates tothe manufacture of condensation products of urea and the like and furi'ural and the like, resulting in the production of useful resins or rubberlike products of a plastic, potentially reactive nature. These products may subsequently be shaped, molded and hardened as through the action of heat or heat and pressure. They are therefore useful plastic, cementitious substances which may be soluble in the usual resinlike solvents such as alcohol, acetone, etc.

Furthermore, these condensation products of urea and iurfural may be considerably altered as by the introduction of various solid or liquid modifying agents and fillers such as, for instance, wood flour, comminuted com cobs, infusorial earth, asbestos; metallic oxides, or camphor, stearic acid, lanolin, China wood oil, etc. When so mixed the characteristics of the product can be considerably altered, as shrinkage stresses can be modified and certain of the lubricants or bodies of a liquid or semi-solid nature will very greatly tendto eliminate brittleness.

This application is a division of our prior application, Serial No. 741,058 filed October 1, 1924, entitled Condensation product and method of making the same, Patent No. 1,827,824, dated Oct. 20, 1931.

.The soluble product is most particularly useful as a varnish for impregnation into various sheetlike or open structuressuch as paper, cloth, asbestos, etc. After the solvent has been evaporated, these structures may be molded into many desired shapes, and when so formed under the combined action or heat and pressure, reaction takes place in situ, resulting in products of an infusible nature which are not readily affected by ordinary solvents and are of great mechanical and dielectric strength.

We have found that under certain conditions of temperature, urea and furiural will readily condense, forming products of a diverse nature; for instance, the two products will readily condense upon being heated to a temperature of 240 F. The reaction at this temperature is extremely energetic and is difficult to control even in glassware, with the result that the usual end product is an amorphous powdery mass which does not have resin or rubberlike characteristics so desirable for plastic molding purposes. If the urea and iuriural, on the other hand are combined by being heated to a temperature of 240 F. in

the presence of an acid or acid salt catalyst such as, for example, hydrochloric and sulphuric acids, and iron and antimonic chlorides, the reaction is not so energetic when being brought-to this temperature and a plastic mass more resinous in character is obtained after steam distillation, preferably under vacuum. This product, however,

it reacted for too long a time at this temperature likewise becomes amorphous and powdery. However, the reaetion mass may be more readily controlled. This material, unlike that made without a catalyst, may be brought to an infusible point by prolonged heating with or without the addition 5 or a small percentage of an active methylene body.

We have found, however, that the ideal reaction product or urea and furlural is produced in the presence rt a small quantity of basic material as a catalyst, such as, for example, ammonia. or sodium carbonate, and upon'the mass reaching a temperature 01280" F. under a reflux condenser, the reaction becomes exothermic and proceedsalong gently so that it may be readily controlled, and in less than two hours time the reaction may be stopped. The reflux condenser may now be inverted and the synthetic water formed together with any uncombined materlal formed may be readily distilled ofi, result ing in a resinous product which is readily soluhie in alcohol, acetone and ether, and insoluble in benzcl and water. Upon prolonged heating, this soluble mass becomes rubbery and then infusible. High temperatures speed up the reaction considerably, and it is therefore desirable, when molding, to heat these plastic products at temperatures somewhat below their point of carbonizaticn. It has been found that other aldehydes have a desirable efl'ect in producing a stong, tough, final product, and therefore it w desirable to introdme intocr combine with the primary reaction products other aldehyde bodies, the preference, however, being for bodies having active methylene groups such as formaldehyde, paraiormaldahyde, formaldehyde and hexamethyleneteixamine. These bodies have a marked accelerating eiiect on the final reactwo hours. At the end or this period, arrange 2 condenser for distillation and distill of! excess materials and synthetic water. Distillation com-' mences at about 220" F. and the temperature may be raised gradually until 317 F. has been reached. However, great care must be exercised not to exceed this temperature inasmuch as the mass will go to infusibility rapidlyat temperatures higher than this.

In appears that this reaction between urea and furfural as above given takes place in equimolecular proportions and that, therefore, larger quanti ties of furfural than those given may be used, but in the end, after distillation, the proportion of combined materials will be substantially the same. i

In place of using aqueous ammonia as a condensing agent, we can use potassium or sodium carbonate, sodium hydroxide, potassium hydroxide and other basic materials.

In our experiments where potassium carbonate was used as a catalyst, it was used in its dry form .in a weight equivalent to one per cent of the total weight of the charge of urea and furfural. Similarly sodium carbonate was also used dry and in the same proportion. The hydroxide of sodium and potassium were first dissolved in water to a strength, and this solution was added to the reacting mass at the rate of 3% of the total weight of urea and furfural.

It is to be understood that acids such as, for example, hydrochloric and sulphuric, acid salts such as, for example, ammonium and iron chloride will cause the reaction to ensue and that these, we have found, may be used in proportions of about one per cent of the weight of the urea and furfural under reaction.

. We have also found it desirable to introduce phina wood oil, lanolin and other modifying agents before mentioned preferably into the reacting mass although for some purposes these modifying agents may be added to the product after the primary reaction has terminated. When China wood oil, for instance, is used, we find that a percentage of say 5% of the weight of urea and furfural produces a mass which is much more flexible than when the China'wood oil is not used. A similar proportion 01 lanolin may be added to the mass after the reaction has been completed and is, say, in its varnish form. This mass produces a product having a lubricant uniformly dispersed throughout and which is therefore admirably suited for cold punching, 'etc.

Wherein we have used the term urea, we wish this to be understood as including not only the substance commonly known as urea or carbamid, but the various derivatives such as benzoyl carbamid, acetyl carbamid and thiourea. And wherein we have used the term furfural, we wish it to be understood as including its homologues, derivatives and substitution products such as,

for example, methylfurfural.

What we claim is 1. The herein described product comprising a plastic resinous condensation product of furfural and urea having China wood oil incorporated therewith.

2. The herein described method of forming a synthetic resinous plastic which comprises heating a mixture of furfural and urea in the presence of a catalytic agent and China wood oil, reacting said mixture until the aldehyde and urea have been substantially combined, and then stopping reaction and removing from the product synthetic water and other volatile substances.

3. A composition of matter resulting from reacting furfural and urea to produce a resinous condensation product and simultaneously combining with said product China wood oil and a reactive methylene body.

EMiL E. NOVOTNY. WILMQTI w. JOHNSON. 

